It has been conventional in the glass fiber forming art to use bushings having orificed projections to flow streams of molten glass material for attenuation into fibers. By using such orificed projections, the undersurface or tip plate of such bushings were less likely to flood with molten glass material during interruption of the fiber forming process. During interruption of the process a tipped bushing will form beads of glass at the exit of each tip rather than forming a large mass of glass covering the entire undersurface of the bushing as in a complete flood.
However, by using bushings which include tips or orificed projections, one is physically limited by the walls of the tips to certain orifice densities in the bottom wall. If the tips or projections can be eliminated from the bottom surface of the bushing, the orifices can be packed more closely together, and thus, higher orifice density bushings can be utilized.
However, utilization of such high orifice density tipless bushings has been limited because of the difficulty of restarting the fiber forming process after an interruption. When the fiber forming process is interrupted when using such a bushing, the undersurface of the bushing quickly floods with molten glass material. Improvement is desired in the method and apparatus for for restarting such bushings after a process interruption.